The present invention relates to an optical device.
A technology for an optical device that performs zooming and focusing is proposed by, for example, Japanese Patent Publication No. 2013-257369. Specifically, such the zooming and focusing are performed by moving a lens unit in an optical axis direction. The lens unit moves in the optical axis direction in conjunction with a cam follower that is engaged with a straight groove and a cam groove by rotating a cam ring in which the cam groove is formed relative to a fixed tube in which the straight groove is formed.
An object of Japanese Patent Publication No.2013-257369 is to provide an optical device that can smoothly perform the zooming and focusing with no influence on the optical performance at any relative angle between the straight groove and the cam groove. Further, in order to accomplish the purpose, the optical device is configured with an optical element, a first lens barrel, a second lens barrel, a cam ring, a first cam follower, a second cam follower, a fixed tube and an energization member. Specifically, the first lens barrel holds the optical element and moves in an optical axis direction of the optical element. The second lens barrel moves in the same direction as the first lens barrel as the first lens barrel moves. The cam ring is configured with first and second cam grooves that respectively displace the first and second cam followers in the optical axis direction. Specifically, the first and second cam followers are connected to the first and the second lens barrels, respectively. The fixed tube is configured with first and second straight grooves that respectively guide the first and second cam followers to the optical axis direction. The energization member that respectively energizes the first and second cam followers in in a direction intersecting the optical axis direction.
With respect to the technology described in Japanese Patent Publication No. 2013-257369, the energization member energizes the component in the direction intersecting the optical axis direction. When the configuration that used the energization member explained above is adopted, it makes the configuration of the optical device complicated, and further, it may cause a problem of such as a durability of the energization member.